Great White Sharks in Cape Cod Rising in Population

In this Tuesday, July 25, 2016, photo released by the Atlantic White Shark Conservancy, a great white shark swims close to the Cape Cod shore in Chatham, Mass. (Wayne Davis/Atlantic White Shark Conservancy via AP)

"We think it’s highly correlated with the growing presence of gray seals in the area," Skomal said. "Big white sharks like to feed on gray seals. Over the course of the last 45 years, the gray seal population is a conservation success story. It has rebounded after protection was put in place in 1972 and that rebounding population now has reached levels that could be an excess of 20 to 30,000 animals in the area and white sharks are drawn to those areas to feed on them."

Since 2014, the number of great whites off Cape Cod has gone from 80 to nearly 150, and already this season at least six sightings of these dangerous sharks have been reported.

"We’ve been studying sharks off the coast of Massachusetts for 30 years and our work with white sharks off Cape Cod is relatively recent," Skomal said on "Good Morning America." "The numbers we’re seeing on a relative scale are increasing, in 2014 we counted 80 individuals over the course of the summer and just last summer that went up to about 147. So there is a general increasing trend as more and more sharks recruit to the area."

"It’s not if, it’s when, in terms of somebody being fatally attacked," Skomal said last year. "We’ve got seals being eaten within 100 meters of surfers. Think about that. Cape Cod is coexisting right now, but we haven’t had the attack; we haven’t had that fatal attack."

"When you’ve got large numbers of sharks, the prey they feed on [seals] and people in the water, the potential of an interaction is there," Skomal said, according to ABC News. "You want the people to be aware of it and that’s really what our goal is. Collect the kinds of data to inform the towns so they can enhance public safety."

"It’s the combination of a large predator and the things they eat, both gaining in population size and both coming back to lay claim to areas that historically were theirs 150 years ago," George Burgess, director of the shark research program at the University of Florida, told the Cape Cod Times in January. "The inevitable conflict is that we have laid claim to those beaches for our recreation and sport."